Change docs license to CC BY-SA 4.0
As discussed in https://gitlab.com/gitlab-org/gitlab-ce/issues/42891, we're changing the docs license to be the same across CE and EE.
With that chance, let's change the Runner docs as well to be consistent.
As discussed in https://gitlab.com/gitlab-org/gitlab-ce/issues/42891, we're changing the docs license to be the same across CE and EE.
With that chance, let's change the Runner docs as well to be consistent.